In various molding/forming machines such as an injection molding machine and a press-forming machine, and a machining device (machining machines) such as a bonding machine, an electrically-powered mechanism (mechanical driving unit) is driven by a motor, thereby applying a pressure on a pressurized target. Moreover, in those machining devices, generally, an actual pressure value, which is a pressure value when the mechanical load is pressed against a material to be molded/formed or the like or a workpiece, which is the pressurized target, is detected, and pressure control is performed based on the detected actual pressure value and a pressure command value. Based on this pressure control, a current command value for the motor is calculated so that the actual pressure value follows the pressure command value.
In this pressure control, as the pressure command signal, which is a signal of the pressure command value, a stepwise signal in which a pressure value considered as the target is a final value is often used. However, by the control applying the stepwise pressure command signal, an overshoot, which is a phenomenon in which the actual pressure value exceeds the target value, is generated. In the pressure control in the molding/forming machine and the bonding machine, the generation of the overshoot generates an actual pressure value excessively larger than the value of the target pressure, resulting in an adverse effect on a quality of molded/formed products and machined products.
In order to address this problem, for example, in a conventional apparatus described in Patent Literature 1, as the pressure command signal, a signal, which rises at an approximately linear rate and reaches a target pressure considered as a target, is used.